The mammalian GABAJbenzodiazepine (GABAJBZ) receptor is comprised of several subunit isoforms: cq6, f3.3, Y,.~ and 6. In the present studies, the expression of (Y,, p2, and y2 subunit mFiNAs was examined in cerebellar Purkinje cells and deep cerebellar neurons of staggerer mutant mice during postnatal development. In control animals, the three subunit mRNAs were present at high density in Purki...

Synapse formation depends critically on the competition among inputs of multiple sources to individual neurons. Cerebellar Purkinje cells have highly organized synaptic wiring from two distinct sources of excitatory afferents. Single climbing fibers innervate proximal dendrites of Purkinje cells, whereas numerous parallel fibers converge on their distal dendrites. Here, we demonstrate that the ...

The cerebellar cortex has a fundamental parasagittal organization that is reflected in the physiological responses of Purkinje cells, afferent and efferent connections, and the expression of several molecular markers. The most thoroughly studied of these molecular markers is zebrin II (ZII; a.k.a. aldolase C). ZII is differentially expressed in Purkinje cells, resulting in a pattern of sagittal...

Non-biased systematic sampling using the principles of stereology provides accurate quantitative estimates of objects within neuroanatomic structures. However, the basic principles of stereology are not optimally suited for counting objects that selectively exist within a limited but complex and convoluted portion of the sample, such as occurs when counting cerebellar Purkinje cells. In an effo...

The contribution of Purkinje cells to cerebellar motor coordination and learning is determined in part by the chronic and acute effects of climbing fiber (CF) afferents. Whereas the chronic effects of CF discharge, such as the depression of conjunctive parallel fiber (PF) inputs, are well established, the acute cellular functions of CF discharge remain incompletely understood. In rat cerebellar...

Loss of Purkinje cells has been implicated in the development of diabetic neuropathy, and this degeneration is characterized by impairment of autophagic processes. We evaluated whether fat-1 transgenic mice, a well-established animal model that endogenously synthesizes ω3 polyunsaturated fatty acids (ω3-PUFA), are protected from Purkinje cell degeneration in streptozotocin (STZ)-treated model w...

The purpose of these experiments was to examine the effects of norepinephrine and propranolol on distal Purkinje fibers of the canine heart. Previous studies have indicated that action potential duration is normally greatest in distal Purkinje fibers 3—4 mm from the Purkinje-muscle junction. In such preparations, premature beats initiated either proximal or distal to the area of maximal action ...

stract-Regional differences in the restitution of action tential duration may be arrhythmogenic. Though such a fference exists at the Purkinje-ventricular interface, restitution netics have not yet been defined between coupled Purkinje and ntricular cells. Thus, the purpose of this study was to termine the effects of coupling on restitution in Purkinje and ntricular cells. DiFrancesco-Noble and...

Membrane potentials and currents of isolated sheep Purkinje and ventricular cells were compared using patch-clamp and microelectrode techniques. In ∼50% of Purkinje cells, we observed action potentials that showed a prominent phase 1 repolarization and relatively negative plateau (LP cells). Action potential configuration of the remaining Purkinje cells was characterized by little phase 1 repol...

The resurgent component of voltage-gated Na+ (Nav) currents, INaR, has been suggested to provide the depolarizing drive for high-frequency firing and to be generated by voltage-dependent Nav channel block (at depolarized potentials) and unblock (at hyperpolarized potentials) by the accessory Navβ4 subunit. To test these hypotheses, we examined the effects of the targeted deletion of Scn4b (Navβ...